UPDATE!
Solution at the end!

Short back story.
Two years ago I moved from Sweden to The Caribbean. I sent a container with a lot of belongings. Naturally I brought my Space Shuttle. It was well over due with a restoration. So before I packed my container I also got some Rotten dog boards from an English online retailer, to go with the container.
So now around X-mas I got that far into the container to bring out the game. It had survived the time in the container well and it was nice to smell the old game smell once again after a few years without it. To save space I mounted the ROM's to the new Rotten Dog boards before packing the container back in 2018.

First my thoughts was to convert it to the 110V here. I have not find a perfect foolproof guide for that so meanwhile I managed to break out 220V from the fusebox.

I changed almost all lamps for LED and some to new bulbs. Rubber also and so on.
The Rotten Dog boards I got was 1 x 9211 and one MDP3211A plus the new ROMS that was needed.
The old boards did not work that good so I cant really switch back and see if they are better.
Now when I connect the Rotten dog boards I notice a few things:

1. U24 (the 6808 chip) is empty. I googled around and also looked into the papers I got with the boards about this, but nothing say this or that. Is it supposed to be that or did I miss something?

2. There is no sound. There is some background noise but that have always been there.

3. On the 9211 there are three LED's. On start the P1A lits up then goes dark. The other two lits up and stay lit. Is that the way they are supposed to behave?

4. In the center of the playfield there is 6 flashers that lits up SPACE and SHUTTLE. These are on all the time now. Never flashes.

5. Player one and two displays is working But the other three is not. When i swap place of the displays I notice that the displays are now dead. I am mentally preparing myself that it is time to get a new display kit and replace all. I assume this have nothing to do with the Rotten Dog board?

6. I tried to look at the components in the game as well on the diagrams and I cant really see anything that would behave differently on 50Hz vs 60Hz. Is there anything that would change now when I run 220V/60Hz instead of the 220v/50Hz back in Sweden?

Apart from above things the game seems to work. GI works. I can start the game and play (only player one and two shows scores). Multiball and all works. So I feel I am close but still no cigar...

Gratefully appreciating all input. Keep in mind that I am in the Caribbean and most likely this is the only pinball game in this region. I dislike to order a lot of things (money and time consuming) and have it shipped with boat here and it turns out isn't the thing I needed. So If anyone have inputs on what is a good solution apart from just buy new everything.

And naturally if anyone who helps out wants to come and play I will provide with cold beer all night long! There is nothing like a cold beer after a day on paradise beaches!!!

Anyone with knowledge in doing magic in this matter?

With help of Internet and great help from Sean P. I found a solution for these issues.
1. I moved one of the old 6808 I had on my old board. That did not work but the second one did. And with that chip I now also have sound so that solved two things of my issues.
2. Above answer
3. No confirmation but it seems to work like this.
4. When changing flasher to LED flasher I had to unsold the pre heat resistor for these flashers. Next to the flashers is a small board and there is a larger warming resistor (See photo) I removed one end of it so if I like I can sold it back to use bulbs in the future (not sure why I want that but like the option). This game also have some flashers in the back box. I did the same there.
5. For the displays I think there is no help but ordering new. I will most likely get the Xpin LED kit for that. Hopefully next week.
6. I have not done more in this issue. I run 220V/60Hz and it works fine so far.

Warming Resistor (resized).png